[macafee2]

Originally Posted by Devilish

Do not fully understand, are you are saying when the FBH fuse is inserted the FBH fires up and runs, without being started by the temperature sensor or a remote switch, or does the air fan run continuously. If the air fan runs continuously and does not stop intil fuse is pulled, then there is a air fan short circuit on the PCB, This will not be a resistor fault, because I have yet to test a resistor that fails closed, they all fail open circuit.

If the FBH actually fires up and runs, diagnosis is simple without a meter. Remove the wire from pin 3 at the switch, if ok fit another switch. If the same, remove pin 3 of the 6 pin connector, if ok, replace the wire to the switch. If when pin 3 is removed the FBH starts and runs, remove pin 1, if ok, it is the sensor, although unlikely.

yes fbh fires up by itself when fuse 8 is in because I think the push on push off switch may be supplying earth due to a wiring fault. This is not happening all the time. The fbh itself seems to be fine. The push on push off switch lights up when pushed on but now even with it off it is glowing
and this is when the fbh is forced to start
macafee2